Touch screen shield

ABSTRACT

A shield that is attachable to a touch sensitive screen is disclosed. The shield may be attached to the touch sensitive screen only at its outer peripheral portion. An air gap is enclosed between the shield and the touch sensitive screen to form a planar air bearing. The shield preferably does not touch the active area of the touch sensitive screen when the user is not touching the shield but only viewing the touch sensitive screen through the shield. This mitigates unwanted optical artifacts such as trapped air bubbles, Newton rings and chromatic interference while maintaining the sensitivity of the touch sensitive screen.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part patent application of U.S. patentapplication Ser. No. 12/780,443 filed on May 14, 2010, the entirecontents of which are incorporated herein by reference.

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not Applicable

BACKGROUND

The present invention relates to transparent films applied to touchsensitive screens for impact and/or scratch protection.

Electronic devices such as the iPhone have a touch sensitive screen bywhich the user may operate the electronic device. The touch sensitivescreen displays electronic buttons and search boxes that the user canselect by touch. These touch sensitive screens are very large andsubject to cracking and scratching during normal use by the user as wellas when the electronic device is dropped. The resulting damage may becostly to repair and may require replacement of the entire electronicdevice or phone. Accordingly, there is a need for a low cost device thatwill cushion and absorb an impact that could break or scratch the glassface of the electronic device and yet not interfere with thefunctionality and sensitivity of the touch screen or the quality of theimage displayed on the screen.

Prior art films do exist that are adhered to the touch sensitive screen.Unfortunately, these protective films leave unsightly air bubblesbetween the transparent protective film and the transparent glass of theelectronic device. Moreover, these films provide no impact absorptionprotection to the glass face.

Based on the foregoing, there is a need in the art for an improvedprotective film for touch sensitive screens.

BRIEF SUMMARY

The touch screen shield disclosed herein addresses the needs discussedabove, discussed below and those that are known in the art.

The touch screen shield disclosed herein may comprise a base transparentlayer that is attached to a touch sensitive screen of an electronicdevice. A planar air bearing may be formed between the base transparentlayer and the touch sensitive screen by attaching only the outerperipheral portion of the base transparent layer to the touch sensitivescreen. The air gap may be continuous and planar between the basetransparent layer and the touch sensitive screen by adhering aprotective liner to the underside of the base transparent layer. Theprotective liner has an outer periphery which is smaller than the outerperiphery of the base transparent layer so as to form a step. When theouter peripheral portion of the base transparent layer is adhered to thetouch sensitive screen, the base transparent layer is placed intotension by the step thereby lifting the protective liner above and offof the touch sensitive screen. Additionally, the adhesive surroundingthe base transparent layer forms an enclosed air gap and traps airbetween the base transparent layer and the touch sensitive screen. Thesefactors promote formation of the planar air bearing between the basetransparent layer and the touch sensitive screen.

The air gap between the base transparent layer and the touch sensitivescreen may also be formed by forming a thick adhesive layer at the outerperipheral portion of the base transparent layer. The adhesive issufficiently thick so that the base transparent layer is lifted off ofthe touch sensitive screen when the touch screen shield is mounted tothe electronic device.

It is also contemplated that in any of the embodiments discussed hereinof the shield, one or more sacrificial layers may be mounted on top ofthe base transparent layer. The sacrificial layers may be removed one ata time from top to bottom as the top most sacrificial layer is damaged.The additional layers provide additional impact protection and retainsflexibility so that touch sensitivity of the touch sensitive screen isnot compromised.

It is also contemplated that the shield may be formed with an opaqueborder (e.g. black, pattern, etc.) to hide air bubbles that might formbetween the outer peripheral portion of the base transparent layer andthe touch sensitive screen.

More particularly, a transparent shield for a touch sensitive screen ofa device is disclosed. The shield may comprise a first transparentlayer, a thin layer of pressure sensitive adhesive and a secondtransparent layer. The first transparent layer may define opposed firstand second sides. The first transparent layer may also define an outerperiphery. The thin layer of pressure sensitive adhesive may be disposedon an outer peripheral portion of the second side of the firsttransparent layer. The second transparent layer may define opposed firstand second sides. The first side of the second transparent layer may beattached to a central portion of the second side of the firsttransparent layer. An outer periphery of the second transparent layermay be smaller than the outer periphery of the first transparent layerso as to define a step.

The outer peripheral portion of the first transparent layer may beattached to the device so that the central portion of the second side ofthe first transparent layer is positioned on top of the touch sensitivescreen of the device. The first transparent layer may be placed intension when the outer peripheral portion of the first transparent layeris attached to the device.

The shield may further comprise adhesive disposed between the centralportion of the second side of the first transparent layer and the secondtransparent layer for attaching the first and second transparent layerto each other. The adhesive disposed on the outer peripheral portion ofthe second side of the first transparent layer may be protected by aremovable liner. The adhesive may form an enclosed air gap between theshield and touch sensitive screen. The enclosed air gap may form aplanar air bearing.

The shield may further comprise one or more transparent sacrificiallayers peelably removable from each other and the first side of thefirst transparent layer so that a top most sacrificial layer may beremoved as desired. The first and second transparent layers may bethicker compared to the one or more sacrificial layers. The sacrificiallayers may have staggered tabs for assisting in the peeling of the topmost sacrificial layer. A peel value between the sacrificial layers maybe progressively stronger as the top most sacrificial layer is peeledaway.

The adhesive and the first and second transparent layers may have adifference in index of refraction less than 0.2.

The shield may further comprise an opaque annular film at an outerperipheral portion of the first transparent layer.

Moreover, a transparent shield for a touch sensitive screen of a deviceis disclosed. The shield may comprise a first transparent layer and apressure sensitive adhesive. The first transparent layer may defineopposed first and second sides. The pressure sensitive adhesive may bedisposed only at an outer peripheral portion of the second side of thefirst transparent layer. The pressure sensitive adhesive may besufficiently thick so as to form an air gap between the firsttransparent layer and the touch sensitive screen when the shield ismounted to the electronic device. The air gap may be a planar airbearing.

The outer peripheral portion of the first transparent layer may beattached to the device so that the central portion of the second side ofthe first transparent layer is positioned on top of the touch sensitivescreen of the device.

The shield may further comprise one or more transparent sacrificiallayers peelably removable from each other and the first side of thefirst transparent layer so that a top most sacrificial layer may beremoved as desired.

The shield may further comprise an opaque annular film at an outerperipheral portion of the first transparent layer.

Additionally, a transparent shield for a touch sensitive screen of adevice is disclosed. The shield may comprise a first transparent layerdefining opposed first and second sides and a first annular filmdisposed only at an outer peripheral portion of the second side of thefirst transparent layer. The first annular film may be sufficientlythick so as to form an air gap between the first transparent layer andthe touch sensitive screen when the shield is mounted to the electronicdevice. The outer peripheral portion of the first transparent layer isattachable to the device so that the central portion of the second sideof the first transparent layer is positioned on top of the touchsensitive screen of the device.

The first annular film may be opaque to hide air bubbles when the shieldis mounted to the device. Additionally or alternatively, an annularportion of the first transparent layer may be opaque. Additionally oralternatively, the shield may further comprise a second transparentlayer with an opaque border adhered on top of the first transparentlayer.

The shield may further comprise at least one sacrificial layer adheredto the first transparent layer. The shield may further comprise a secondtransparent layer with an opaque border adhered on top of any one of thesacrificial layers.

An index of refraction between the sacrificial layers and the firsttransparent layer may be less than about 0.2.

Additionally, a method for forming a shield for a touch sensitive screenof an electronic device is disclosed. The method may comprise the stepsof nipping first and second films together; cutting out a centralportion of the first and second films for providing an air gap when theshield is mounted to the touch sensitive screen of the electronicdevice; and nipping a third film to the first and second films.

The first and second films may be a protective liner and an opaque film,respectively. The opaque second film may hide air bubbles that may formwhen the shield is mounted to the touch sensitive screen of theelectronic device. The third film is a protective film for mitigatingscratches on the touch sensitive screen.

The method may further comprise at least one sacrificial layer adheredto the third film.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the various embodimentsdisclosed herein will be better understood with respect to the followingdescription and drawings, in which like numbers refer to like partsthroughout, and in which:

FIG. 1 is an exploded top view of an electronic device with a shieldmountable thereon;

FIG. 2 is a cross sectional view of the shield shown in FIG. 1;

FIG. 3 is a cross sectional view of the shield mounted to the electronicdevice shown in FIG. 1;

FIG. 4 is a cross sectional view of a second embodiment of the shieldshown in FIG. 1;

FIG. 5 is a cross sectional view of the second embodiment of the shieldand the electronic device shown in FIG. 1;

FIG. 6 is a top view of the electronic device shown in FIG. 1 with ashield having an opaque border for hiding air bubbles;

FIG. 7 is a cross sectional view of a first embodiment of a shield withan opaque border attached to the electronic device shown in FIG. 6;

FIG. 8 is a cross sectional view of a second embodiment of a shield withan opaque border attached to the electronic device shown in FIG. 6;

FIG. 9 is a top view of a stack of sacrificial layers with tabs forpeeling a topmost layers, the stack being mountable to the shield shownin FIGS. 1-8;

FIG. 10 is a top view of a stack of sacrificial layers with a stair stepconfiguration for peeling a topmost layer, the stack being mountable tothe shield shown in FIGS. 1-8;

FIG. 11A is a cross sectional view of the stair step shown in FIG. 10;and

FIG. 11B is an alternative arrangement to the stair step shown in FIG.11A

FIG. 12 is a top view of an electronic device (e.g., ipad) having adifferent configuration compared to the electronic device shown in FIG.6;

FIG. 13 is an exploded perspective view of a shield comprising a stackof sacrificial layers with an opaque border; and

FIG. 14 is a schematic diagram for forming the shield.

DETAILED DESCRIPTION

Referring now to the drawings, a shield 10 for a touch sensitive screen12 is shown. The shield 10 protects the touch sensitive screen 12 fromscratches, impacts, etc. The shield 10 is damaged instead of the touchsensitive screen 12. When the shield 10 is scratched, dented, etc. to adegree that makes viewing the touch sensitive screen 12 unacceptable forthe user, the shield 10 may be replaced with a new shield 10.Optionally, the shield 10 may have one or more sacrificial layers 14which may be individually peeled off from each other starting from thetop most layer going down to the base shield 10 as the top mostsacrificial layer 14 is damaged. The sacrificial layers 14 a-h may bemounted on top of the shield 10, 10 a. When the shield 10 is attached tothe touch sensitive screen 12, an air gap 16 (see FIG. 3) may be formedbetween the shield 10 and an active area 18 of the touch sensitivescreen 12. The air gap 16 eliminates unwanted optical artifacts such astrapped area bubbles. Newton rings and chromatic interference whilemaintaining the sensitivity of the touch sensitive screen 12.

The air gap 16 may be formed by providing a base transparent layer 20which defines an exposed side 22 and an interior side 24 (see FIG. 3).The interior side 24 may be coated with a pressure sensitive adhesive 26(e.g., acrylic adhesive). The pressure sensitive adhesive 26 may coverthe entire interior side 24 of the base transparent layer 20. Aprotective liner 28 may cover the pressure sensitive adhesive 26 coatedon the interior side 24 and be attached to the protective liner 28. Whenthe shield 10 is ready to be mounted to the touch sensitive screen 12,an outer peripheral portion 30 (see FIG. 2) or annulus of the protectiveliner 28 may be removed from the base transparent layer 20 to expose theadhesive 26 only at the outer peripheral portion of the base transparentlayer 20 on the interior side 24. A step 27 (see FIGS. 2 and 3) isformed at the outer peripheral edge of the protective liner 28. Theshield 10 may be attached to the touch sensitive screen 12 as shown inFIG. 3. More particularly, the entire outer periphery of the basetransparent layer 20 may be adhered to the touch sensitive screen 12 soas to form an enclosed air gap 16 and form a planar air hearing. Thebase transparent layer 20 is tensioned about the step 27. Since aninterior side 32 (see FIG. 3) of the protective liner 28 does not haveany adhesive, a continuous air gap 16 may be formed between theprotective liner 28 and the exposed side 34 of the touch sensitivescreen 12.

Alternatively, a base transparent layer 20 a may be provided with anadhesive 26 a only on the outer peripheral portion 36 of the basetransparent layer 20 a, as shown in FIG. 4. The shield 10 may beattached to the touch sensitive screen 12 by way of the adhesive 26 a,as shown in FIG. 5. The adhesive 26 a may be sufficiently thick suchthat upon adhesion of the base transparent layer 20 a to the touchsensitive screen 12, air gap 16 a is formed, as shown in FIG. 5.

Moreover, it is contemplated that an opaque film 52 (see FIGS. 6-8) maybe disposed at the outer peripheral portion 36 of the base transparentlayer 20 to hide any air bubbles 60 that might form between the outerperipheral portion 36 of the base transparent layer 20 and the touchsensitive screen 12.

More particularly, referring now back to FIG. 1, an electronic device 38such as an iPhone is shown. It is also contemplated that the electronicdevice 38 may be any type of visual display for photographs, video, etc.The electronic device 38 may have a touch sensitive screen 12 whichallows a user to operate the electronic device 38. The touch sensitivescreen 12 may define an active area 18. In the active area 18, the usermay depress various electronic buttons, keys, etc. electronicallydisplayed on the active area 18 to operate the electronic device 38 soas to play video, navigate, start applications, etc. The active area 18may be disposed adjacent or enclosed within an inactive area 42.

The active area 18 of the touch sensitive screen 12 may be protected bydisposing the shield 10 over the touch sensitive screen 12. To this end,the shield 10 may be adhered to the touch sensitive screen 12 whereinonly the outer peripheral portion of the shield 10 is adhered to thetouch sensitive screen 12. A continuous air gap 16 may exist between thecentral portion 44 of the shield 10 and the touch sensitive screen 12.Preferably, the adhesive 26 used to adhere the outer peripheral portionof the shield 10 to the touch sensitive screen 12 contacts only theinactive area 42. However, it is also contemplated that the adhesive 26may adhere the shield 10 also to an outer peripheral portion of theactive area 18.

Referring now to FIGS. 2 and 3, the shield 10 may comprise the basetransparent layer 20. The base transparent layer 20 may be fabricatedfrom a transparent material (e.g., biaxially-oriented polyethyleneterephalate material (boPET), etc.). The base transparent layer 20 maybe approximately 4 mil thick (i.e., 0.004″). Adhesive 26 may be coatedon a majority, if not the entire, interior side 24 of the basetransparent layer 20. To protect the adhesive 26 from dirt and grimeprior to installation on the touch sensitive screen, the protectiveliner 28 may cover the entire interior side 24 of the base transparentlayer 20. The adhesive 26 attaches the protective liner 28 to the basetransparent layer 20. A cut or slit 46 may be made through theprotective liner 28 so as to define an outer peripheral portion 30 orannulus of the protective liner 28 and a central portion 48 of theprotective liner 28. The cut or slit 46 may be made with a rotary die,steel rule die, lasers or other methods known in the art.

When the user is ready to attach the shield 10 to the touch sensitivescreen 12 of the electronic device 38, the user removes the outerperipheral portion 30 of the protective liner 28 from the shield 10 asshown in FIG. 2. For example, the user may apply a small piece of tapeto the outer peripheral portion 30 and peel the outer peripheral portion30 off of the base transparent layer 20. This exposes the adhesive 26only at the outer peripheral portion 36 of the base transparent layer20. This also creates the step 27 between the protective layer 28 stillremaining on the base transparent layer 20 and the base transparentlayer 20. The user aligns the shield 10 to the touch sensitive screen 12and applies pressure to the outer peripheral portion 36 of the basetransparent layer 20 so that the adhesive 26 adheres the basetransparent layer 20 to the touch sensitive screen 12. Preferably, theadhesive 26 is disposed only on the inactive area 42 of the touchsensitive screen 12. The adhesive 26 traps air between the basetransparent layer 20 and the touch sensitive screen 12 to form theenclosed air gap 16. Also, the air gap 16 (see FIG. 3) may define aplanar air bearing due to tension applied to the base transparent layer20 about the step 27. The enclosed air gap 16 and the tension lifts theshield 10 off of active area 18 to form a planar air bearing to mitigateunwanted optical artifacts such as trapped air bubbles, Newton rings,and chromatic interference while maintaining the sensitivity of thetouch screen. It is also contemplated that the adhesive 26 may bedisposed on a portion of the active area 18 at the outer peripheralportion of the active area 18. In this manner, a majority of the activearea 18 has an air gap 16 between the touch sensitive screen 12 and theshield 10.

Optionally, the shield 10 may have one or more sacrificial layers 14a-n. The sacrificial layers 14 may be adhered to each other by way of apeelable adhesive disposed between each of the sacrificial layers 14 aswell as a bottommost sacrificial layer 14 a and the exposed side 22 ofthe base transparent layer 20. During use of the electronic device 38,the topmost sacrificial layer 14 c may become dented, scratched, etc. orotherwise damaged such that viewing through the shield 10 may beunacceptable. At this point, the topmost sacrificial layer 14 c may beremoved (e.g., peeled) from the shield 10. This uncovers a fresh, cleansacrificial layer 14 b. The other sacrificial layers 14 b and 14 a maybe removed top-down as the topmost sacrificial layer 14 becomes damaged.There may be one or more sacrificial layers 14 a-n or stack ofsacrificial layers 14 a-n adhered to the base transparent layer 20.Preferably, there are between two (2) to ten (10) sacrificial layers 14a-n. The sacrificial layers 14 a-n may be fabricated from a transparentmaterial such as biaxially-oriented polyethelene terephalate (boPET).

Referring now to a second embodiment shown in FIGS. 4 and 5, a shield 10a may comprise base transparent layer 20 a. A thick coat of adhesive 26a may be applied only to the underside of the outer peripheral portion36 a of the base transparent layer 20 a. Protective liner 28 a may beplaced over the thick adhesive coating 26 a to protect the adhesive 26 afrom dirt and grime up until prior to installation of the shield 10 a tothe touch sensitive screen 12. After removing the protective liner 28 afrom the shield 10 a, the shield 10 a is aligned to the touch sensitivescreen 12. In particular, the adhesive 26 a is preferably aligned to theinactive area 42 of the touch sensitive screen. Air gap 16 a is formedbetween the base transparent layer 20 a and the touch sensitive screen12. The thick adhesive 26 a lifts the base transparent layer 20 a off ofthe active area 40 to form the planar air bearing, as shown in FIG. 5.

Optionally, one or more sacrificial layers 14 a-n as discussed above inrelation to FIGS. 2 and 3 may be mounted to the shield 10 a. Thesacrificial layers 14 a-n may be removed one by one as the topmostsacrificial layer is damaged (e.g., dented, scratched, etc.).

Referring now to FIGS. 6-8, an opaque annular film 52 may be interposedbetween the outer peripheral portion 36 of the base transparent layer20, 20 a and the touch sensitive screen 12. The opaque annular film 52may be incorporated into the shields 10, 10 a discussed in relation toFIGS. 2-5. The opaque annular film 52 may be black, dark color,patterned, etc. so long as the pattern or color hides or mitigatesvisibility of air bubbles 60. The opaque transparent layer 52 hides anyair bubbles 60 that may exist when attaching the shield 10, 10 a to thetouch sensitive screen 12. FIG. 6 illustrates a black border. However,upon further inspection of the border area in FIGS. 7 and 8, an airbubble 60 exists between the shield 10, 10 a and the touch sensitivescreen 12. Nonetheless, due to the opaque annular film 52, such airbubble 60 is not noticeable or is not as noticeable when viewing thetouch sensitive screen 12.

More particularly, referring now to FIG. 7, the shield 10 a may have anadhesive 26 b disposed about the outer peripheral portion 36 of the basetransparent layer 20 b. The opaque annular film 52 may be attached tothe base transparent layer 20 b by way of the adhesive 26 b. Adhesive 54may now be coated, sprayed or disposed onto the bottom surface of theopaque annular film 52 for attachment of the shield 10 a to the touchsensitive screen 12. The adhesive 26 b may be thin so as to notappreciably add to the thickness of the base transparent layer 20.Alternatively, the adhesive 26 b or 54 may be thick such as in theembodiment disclosed in FIGS. 4-5. Nonetheless, the film 52 and/or theadhesive 26 b, 54 may independently or collectively be sufficientlythick so that the air gap 16 a may be formed between the shield 10 a andthe touch sensitive screen 12.

Sacrificial layers 14 a-n may be stacked on top of the base transparentlayer 20 a as discussed above in relation to FIGS. 2-5.

Referring now to FIG. 8, the shield 10 may also have an opaque annularfilm 52. The opaque annular film 52 may be disposed at the outerperipheral portion 36 of the base transparent layer 20. Preferably, theopaque annular film 52 and the adhesive 26, 54 is thinner than theprotective liner 28, and more particularly, is thinner than the centralportion 48 of the protective liner 28. The step 27 is formed at theouter peripheral edge of the protective liner 28. The opaque annularfilm 52 shown in FIG. 8 is attached to the base transparent layer 20 byway of adhesive 26. Adhesive 54 may be applied to the underside of theopaque annular film 52 to attach the shield 10 to the touch sensitivescreen 12. Sacrificial layers 14 a-n may also be stacked on top of thebase transparent layer 20 as discussed above in relation to FIGS. 2-5.

An index of refraction of the adhesive and the transparent materialwhich forms the sacrificial layers 14 a-n, base transparent layer 20 andthe protective liner 28 may have a refraction mismatch of 0.2 tominimize unwanted internal reflection, haze, maximize transmissions andcontrast of the screen and to maintain the high brightness and contrastof the visual objects displayed on the touch sensitive screen 12. It isalso contemplated that the upper surface of each of the sacrificiallayers 14 and the exposed side 22 of the base transparent layer 20 mayhave a thin hard coating. The adhesive that attaches each of thesacrificial layers 14 together as well as the stack of sacrificiallayers 14 to the base transparent layer 20 may be provided so that thepeel strength is the same throughout the stack. Alternatively, thebottom most layer 14, 20 may have a higher peel value than the layers 14above the bottom most layer 14, 20. In this manner, as the topmostsacrificial layer 14 is peeled from the lower sacrificial layers 14, theact of peeling the topmost sacrificial layer 14 does not also peel thelower sacrificial layers 14. The peel strength may range between about25 to about 300 grams/inch. The adhesive discussed herein may bepermanently attached to the layer immediately above the adhesive.Accordingly, when the topmost sacrificial layer 14 is peeled, no residueof the adhesive is left on the layer below. The exposed or top side ofthe fresh sacrificial layer 14 mostly, if not entirely is free fromadhesive. Additionally, when all of the sacrificial layers 14 areremoved from the shield 10, no adhesive residue is left on the exposedside 22 of the base transparent layer 20.

Each of the sacrificial layers 14, base transparent layer 20 and theprotective layer 28 may have a thickness between about 1 mil to about 7mil with each mil being 0.001″ thick. Unless otherwise stated, theadhesive layer attaching the sacrificial layers 14 to each other as wellas the sacrificial layers 14 to the base transparent layer 20 may addnegligible thickness to the shield 10, 10 a. By way of example and notlimitation, if each of the sacrificial layers 14, the base transparentlayer 20 and the protective layer 28 have a thickness of 2 mil, then thetotal thickness of the shield 10 may be 8 mil thick provided that thereare only two sacrificial layers 14 and one base transparent layer 20 andone protective liner 28.

The sacrificial layers 14 a-n may be stacked upon each other.Preferably, the sacrificial layers may be generally coextensive witheach other so that the stack of sacrificial layers 14 a-n appear to be asingle film. As discussed above, in order to assist in the peeling ofonly the top most sacrificial layer 14 while leaving the lowersacrificial layers 14 in place, the adhesive peel strength may beadjusted to be the weakest at the top most sacrificial layer andstronger as the top most sacrificial layer is peel away. Alternatively,or additionally, tabs 56 which are shown in FIG. 9 may be formed as partof the sacrificial layers 14. Each of the sacrificial layers 14 a-n maybe formed with the tab 56 that extends outward as shown in FIG. 9. Noadhesive is formed on the area of the tab 56. Each of the tabs 56 may beoffset or staggered with the tabs 56 of the other sacrificial layers sothat the user can pull the tab 56 of the then top most sacrificial layerat the time to peel off the top most sacrificial layer 14. Other tabbingsystems known in the art may be incorporated such as those shown anddescribed in relation to Japanese Kokai Patent Publication Number4-314537 and U.S. Pat. No. 6,777,055.

Additionally or alternatively, a peel assist system shown in FIGS.10-11B may be incorporated into the shield 10, 10 a. By way of exampleand not limitation, a corner of the shield 10, 10 a may have a stairstep configuration. Although the upper left corner of the shield 10, 10a is shown as having the stair step configuration, any of the othercorners, upper right, lower left and/or right corners may have the stairstep configuration. A first configuration of the stair step is shown inFIG. 11A. Sacrificial layers 14 may be peeled off layer by layer. Thetop most sacrificial layer 14 may be peeled off with the aid of a sharpblade or fingernail that digs between the first and second top mostlayers 14 as shown by arrow 62 to initiate peeling of the top most layer14. FIG. 11B illustrates a second configuration of the stair stepconfiguration. The stair step configuration is reverse compared to thestair step configuration shown in FIG. 11A. The user may lift the topmost layer 14 with his or her finger since the top most layer 14 extendsover the rest of the stack of layers 14. The shield 10, 10 a has beenshown generically attached to the electronic device 38 for the purposesof clarification. However, any of the attachment methods discussedherein may be implemented in the shield 10, 10 a embodiments shown inFIGS. 10-11B.

Certain embodiments of the shield 10 above were directed to amulti-layer shield 10. Either the base transparent layer 20 was adheredto a lower protective layer 28 and/or one or more sacrificial layers 14a-n. These layers 20, 28, 14 a-n are each adhered to each other. Thelayers 20, 28, 14 a-n and the adhesive may absorb impact shock causedwhen the electronic device 38 is dropped or the touch sensitive screen12 hits a solid object. The impact is reduced at each adhesive interfacewhere the softer adhesive may yield and spread out the impact forcelaterally instead of proceeding directly into the glass of the touchsensitive screen. Additionally, the stacked construction of the shield10 and the sacrificial layers 14 a-n retain the flexibility orbendability of the layers to maintain the tactile response for the touchsensitive screen.

Preferably, the base transparent layer 20, protective layer 28, andsacrificial layers 14 are fabricated from biaxially orientedpolyethelene terephalate material (boPET).

Referring back to FIG. 1, the various embodiments of the shield andsacrificial layers disclosed herein may be enlarged to cover the frontsurface of the electronic device 38. An example of the enlarged shieldis shown in FIG. 1 in hidden lines. Cutouts 58 may be made through theshield to allow for physical buttons and speakers on the electronicdevice 38.

In lieu of the opaque annular film 52, it is also contemplated that thebase transparent layer 20, 20 a may have an opaque printed border whichserves the same function as the opaque annular film 52. The opaqueborder on the base transparent layer 20, 20 a may be formed by a screenprinting, etc. or other methods known in the art. It is alsocontemplated that the adhesive 26, 26 a, 26 b, 54 may be colored so asto be opaque and hide the air bubbles 60.

Referring now to FIG. 12, a shield 10 b for an electronic device havinga different configuration (e.g., iPad) is shown. The shield 10 b mayhave the same structure as the shield described in relation to FIG. 6.The shield 10 b is configured to fit a touch sensitive screen of theelectronic device. However, other configurations are also contemplated.Both shields 10 a, 10 b shown in FIGS. 6 and 12 may be fabricated in thefollowing manner. The following description is in relation to the shield10 b shown in FIG. 12. However, the following discussion is alsoapplicable to fabrication and structure of the shield 10 a and shieldhaving other configurations.

Referring now to FIG. 13, the shield 10 b may have a base layer 20 b. Anopaque annular film 52 b may be adhered to the bottom side of the basetransparent layer 20 b through a pressure sensitive adhesive 26 c. Thebase layer 20 b and opaque annular film 52 b may be adhered to the touchsensitive screen 12 of the electronic device by way of adhesive 54. Theadhesive 54 may be protected from dirt and grime by way of a releaseliner or protective liner 28 b until the user is ready to attach theshield 10 b on the iPad or touch sensitive screen of the electronicdevice. The protective liner 28 b may be removed immediately prior tomounting the shield 10 b to the touch sensitive screen 12 of theelectronic device. As discussed above, one or more sacrificial layer 14a, 14 b, 14 n may be mounted to the top side of the base transparentlayer 20 b. A protective liner 64 may be adhered to the top mostsacrificial layer 14 b to protect the top most sacrificial layer 14 bfrom unnecessary scratches during storage and transport to the end user.The protective liner 64 may be removed from the top most sacrificiallayers 14 b immediately before but preferably after mounting the shield10 b to the touch sensitive screen of the electronic device.

Referring now to FIG. 14, a process for fabricating the shield 10 b isshown. The opaque annular film 52 b may initially be provided as a rollof film 66. Also, the release liner 28 b and adhesive 54 may be providedas a roll of film 68. The rolls of film 66, 68 may be nipped together byrollers 70 a, 70 b. As the roll of film 68 is being unrolled, aprotective liner 72 may be removed from the roll 68 of film to exposethe adhesive 54 so that the adhesive 54 adheres to the opaque coloredfilm 52. When the film 68, 66 is disposed between the rollers 70 a, 70b, the release liner 28 b is adhered to the opaque film 52 by adhesive54. After the nipping operation 74, the center portion 71 (see FIG. 13)which defines air gap 16 a is cut out during the center cuttingoperation 76. After the center cutting operation 76, a protective liner78 protecting adhesive 26 c may be peeled off and discarded as shown inFIG. 14. The base transparent layer 20 b along with the optionalsacrificial layers 14 may be provided as roll 88 and may then be nippedto the opaque annular film 52 by rollers 80 a, 80 h. After the basetransparent layer 20 and the sacrificial layers 14 are nipped to theopaque annular film 52 b, the stack may undergo a final outer peripherycutting operation 82. During the final cutting operation 82, the outerperiphery of the shield 10 b is cut. Additionally, any other aperturethat needs to be cut throughout the entire stack is also performed. Byway of example and not limitation, the center hole 82 for pressing upona joy stick of the electronic device is cut during the final cuttingoperation 82.

Instead of disposing an opaque annular film 52 b below the basetransparent layer 20 b, it is also contemplated that a film 84 may bedisposed above the base transparent layer 20 b as shown in FIG. 13. Thefilm 84 may have an opaque border 86. The center portion 73 may betransparent. The film 84 may have the same structure as the sacrificiallayers 14 a, 14 b and the base transparent layer 20 b with respect toindex of refraction and clarity. It is also contemplated that the film84 may replace the base transparent layer 20 b or any one of thesacrificial layers 14 a, 14 b. It is also contemplated that a coloredadhesive may be laid on the border of any one of the base transparentlayer 20 b, or sacrificial layers 14 a, 14 b.

The above description is given by way of example, and not limitation.Given the above disclosure, one skilled in the art could devisevariations that are within the scope and spirit of the inventiondisclosed herein, including various ways of forming the slit for theannular ring. Further, the various features of the embodiments disclosedherein can be used alone, or in varying combinations with each other andare not intended to be limited to the specific combination describedherein. Thus, the scope of the claims is not to be limited by theillustrated embodiments.

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 14. (canceled)
 15. (canceled)16. A transparent shield for a touch sensitive screen of a device, theshield comprising: a first transparent layer defining opposed first andsecond sides; a first annular film disposed only at an outer peripheralportion of the second side of the first transparent layer, the firstannular film being sufficient thick so as to form an air gap between thefirst transparent layer and the touch sensitive screen when the shieldis mounted to the electronic device; wherein the outer peripheralportion of the first transparent layer is attachable to the device sothat the central portion of the second side of the first transparentlayer is positioned on top of the touch sensitive screen of the device.17. The shield of claim 16 wherein the first annular film is opaque tohide air bubbles when the shield is mounted to the device.
 18. Theshield of claim 16 wherein an annular portion of the first transparentlayer is opaque.
 19. The shield of claim 16 further comprising a secondtransparent layer with an opaque border adhered on top of the firsttransparent layer.
 20. The shield of claim 16 further comprising atleast one sacrificial layer adhered to the first transparent layer. 21.The shield of claim 20 further comprising a second transparent layerwith an opaque border adhered on top of any one of the sacrificiallayers.
 22. The shield of claim 18 wherein an index of refractionbetween the sacrificial layers and the first transparent layer is lessthan about 0.2.
 23. A method for forming a shield for a touch sensitivescreen of an electronic device, the method comprising the steps of:nipping first and second films together; cutting out a central portionof the first and second films for providing an air gap when the shieldis mounted to the touch sensitive screen of the electronic device; andnipping a third film to the first and second films.
 24. The method ofclaim 23 wherein the first and second films are a protective liner andan opaque film, respectively, and the opaque second film hides airbubbles that may form when the shield is mounted to the touch sensitivescreen of the electronic device.
 25. The method of claim 24 wherein thethird film is a protective film for mitigating scratches on the touchsensitive screen.
 26. The method of claim 24 further comprising at leastone sacrificial layer adhered to the third film.